Flow controller



April 24, 1951 H. u. GARRETT ET AL 2,550,410

FLOW CONTROLLER Filed Aug. 29, 1947 ATTORNEYS Patented Apr. 24, 1951 UNITED STATES ATENT OFFICE 2,550,410 FLOW CONTROLLER Henry U. Garrett and Cliiford M. Peters, Lngview, Tex.', assignors, by direct and mesne assignments, to Garrett Oil-Tools, Inc., Houston, Tex a corporation'of Texas Application August 29, 1947, Serial No. 771,159

Apparatus in accordance with this invention may be used for example for controlling the flow. of gas in-gas lift operations in the production of, oil from well bores where it is necessary to intermittently introduce a charge of lifting fluid under pressure into a column of liquid. The controllers of this invention have many other uses. and this specificuseis. given by way of, 11- V lustration. and. not by wayv of limitation.

An object of' this invention is to provide a simple, and economical controller for how through aconduit.

Another object is to. provide. a simple,- and economical. controller forfiow through a. conduit inswhich the flow takes, place during pred'eter,.

mined time intervals.

A. further object is to provide a, simple economical controller for flow, through a conduit wherein. flow is provided, for, during predeter- -mined time. intervals. in which the. conduit will not be open, for flow during any, of the time intervalsin the event the pressure on the downSim-(earnv side, offthe controller exceeds a. predetermined; amount.

Y .et anotheliobject' is to provide a simple economical controller for fljow through a conduit. wherein. flow, is provided for during predeterminedj time intfervals, in which the length of the time. intervals during which flow occurs may be varied,

"Still'another object is to provideasa sub-combination for a flow controller a, time controlledmechanism in, which the length of a predeterminednumber of time intervals'may be readilyvaried.

Other and further objects of this invention willappear from the following description:

' In the accompanying drawings. which form a part, of the instant specification and are to be read'in conjunction therewith, the single figureillustrates schematically, in. elevation and installation ofa flow controller embodying this inventionwherein pajrtsare shown in sectionfor added clarity;

Referring to the drawings;,the flow controller is illustrated in conjunction with a well head; 5' of a producing oil well which is equipped for, operation by what is known as the gas liftv method. In this particular installation the well; head" dismounted; upon the upperendof an oil' string of1 casingv 6; Suspended, concentrically within the casing 6 is a string offlow tubing '1; Thisequipment may be, in accordance with con- 7 Claims. (Cl. 137-145) ventional practices and in the interest of simplicity a more detailed illustration of the well bore equipment is not shown in the drawings. Itis to be understood, however, that the string of tubing is equipped with suitable gas lift valves at proper intervals throughout its length and that in operation gas or other lifting fluid is introduced, in this example, into the annulus,

formed between the casing 6 and the tubing 1.

. This gas is introduced through conduit 8.

In gas lift operations the gas is introduced into. the casing tubing annulus intermittently andthe,

gas lift valves, which are pressure responsive valves, are operated by the pressure variations The controller of this invention forms a compact unit that may. be readily mounted upon the conduit 8 and of the fluid in the annulus.

governsthe flow of fluid through the conduit into the annulus so that lifting fluid under, pressure is introduced into the annulus periodically at predeterminedtime intervals, but the arrangement of the controller is such that the motor valve,

will not open even during one of the predetermined time intervals if for any reason the pressure within the annulus is greater than a, prede'e termined amount. Obviously such a pressure condition would occur only in the event of un-,-

usual'circumstances in which case it is desirable that the line 8 be kept in a closed condition.

With regard to the flow controller, which con.

stitutes the invention, it is made up of a motorvalve 9 and a time controller [0. The motorvalve, comprises a valve body II, a valve stem housing I2, head bushing l3 and a two part diaphragm casing M.

The motor-valve may be interposed in conduit- 8 as body II has threaded connections at both The body has a partition 15 across the valve stem. This part has a portion of enlarged diameter which resides within the portion l-2a of the housing bore. A seal is provided between the housing and part ll by O-rings t8 disposed in peripheral grooves in the enlarged diameter portion of part ll to prevent escape of fluid under pressure.

such as for instance chevron packing in lieu of of the O-rings but the O-rings have been found to be entirely satisfactory for this purpose and'due to the very low friction involved in their use are preferred. Also, a bellows type seal may be employed. The part ll carries valve member 19 r at its lower end. The valve member is in the The part Il may be equipped with other types of packing or sealing material form of a hemisphere and is adapted to seat on seat ring it to close off the passage through the valve member and control flow through conduit 8.

The bushing 53 has a threaded connection with the upper end of housing 12 and has a central bore axially aligned with the bore of the housing. Another part 23 of the valve stem is slidably inserted within the bore of bushing l3 and extends from the upper end thereof through a bore in the lower part of the diaphragm casing 24, which is secured to the upper end of bushing l3 by set screws 2i. Part 23 of the valve stem carries at its upper end a diaphragm plate 22 which be integral therewith. The diaphragm plate resides within the chamber 23 and contacts the underside of diaphragm 24 which divides chamber 23 into 2 parts. The lower part of the charmoer is in communication with the atmosphere through port-s l4a and the upper part of the chamber has a connection l4?) which receives a line 25. Line 25 communicates with a source of actuating fluid under pressure for energizing the motor of the valve.

It is believed that the operation of the motorvalve is apparent from its foregoing description. The diaphragm 24 is subjected to the pressure differential thereacross and urges the valve stem, made up of parts ll and 23, downwardly to seat valve member it against seat ring 18. With the valve member i3 seated the pressure to be controlled is exerted against the valve member on an area equal to the area of the seat. The force of the pressure against this area urges the valve stem upwardly against the diaphragm, but due to the substantially greater area of the diaphragm as compared with the area of the seat, the pressure within the upper part of chamber 23 may be relatively small as compared with the pressure controlled. With valve member l9 lifted from its seat, which may be accomplished in a manner hereinafter explained, the area exposed to pressure within the valve body is equal to the area of the lower end of the enlarged portion of part ll of the valve stem. Thus, it will be seen that at all times the valve stem has a part exposed to the pressure to be controlled and that the area of this part is greater with the valve member removed from its seat than with the valve member closed. Thus, when the pressure conditions within the valve body and the upper part of chamber 23 are such that the valve member is cracked from its seat force tending to unseat the valve member is increased somewhat and results in a snap action of the valve where the pressure downstream from seat IE is less than that upstream of the seat with the valve member i9 seated which is normally thecase when the valve is to be opened' The time controller and its connection with the motor valve provides a means for relieving the pressure within the upper part of chamber 23 in order that the valve member l3 may be shifted to open position.

The time controller it may be any suitable conventional time controlled unit and the one illustrated schematically is the type driven by fluid under pressure but it is contemplated that the unit may be driven electrically or otherwise. The unit may be mounted upon the conduit 8 by means of a support bracket 2?.

The tin e controller has a disc 28 which is rotatably mounted and has a plurality of pins 29 extending laterally thereof. The pins 23 are arranged circumierentially about the axis of rotation of disc 28. The disc 23 is rotated by suitable mechanism which, in this instance is a fluid driven motor. The fluid line 23 leads to a suitable source of drive fluid which may be the regulator 36.

A control lever 30 is pivoted at one end at 3| and the vent part 32 is arranged to engage the free end of lever 36 and serves as a stop to prevent rotation of the lever in one direction. A member 33 with a tapered or conical end extends from lever 33 and the tapered end is adapted to engage the outer peripheries of pins 29 as the pins are passed beneath the member 33. Engagement of a pin 29 with the tapered end of member 33 and continued rotation of the disc 28 results in a raising of the free end of lever 3i] from the vent part 32. On continued rotation of the disc the free end of lever 33 is again lowered into contact with the vent part 32. By adjusting the position of member 33 axially relative to lever 30 the length of time that the free end of lever 35 will be raised from vent part 32 upon engage-- ment of the member 33 with each of pins 29 may be varied from a time interval of maximum length to one of very short duration.

Member 33 in this embodiment is shown as a screw which facilitates its axial adjustment to vary the position of its tapered end relative to lever 30. Simple rotation of the screw obviously will provide this adjustment.

The time control operation of lever 33 is utilized to provide for venting of actuating pressure fluid from the upper part of chamber 23. However, as a preface to the explanation of this operation, the connection of line 25 with a source of actuating fluid will be first explained. The connection '25 communicates through choke 34 with a connection 35 on regulator 33. The regulator has a connection with conduit 5 through line 31. Thus the upper portion of chamber 23 is charged with a constant or pilot pressure from regulator 35. when the lever 30 is raised from the vent part 32. The vent part contacts a resilient insert in the underside of lever 30 which closes the part. With the lever 30' raised the vent part communicates between the atmosphere and the upper portion of chamber 23 through conduit 38, valve 39, conduit 43 and connection 25. Due to the choke or restrictor 34, fluid under pressure is bled through the vent connection more rapidly than the pressure fluid is charged to the valve motor when the lever is raised from the vent part 32.

The valve 39 is interposed in the connection between vent part 32 and connection 25 to provide a means for preventing the relief of the pressure from the upper portion of chamber 23, on raising of lever 30, in the event the pressure within conduit 8 downstream from valve I9 exceeds a predetermined maximum. Thus, the downstream pressure in conduit 8 serves as a control pressure. The valve includes a casing made up of a cylindrical portion 4| and a port portion 42. The latter portion has an endwise passage 42a communicating with conduit 38 and a laterally extending passage 42b communicating with conduit 40. Part 42 has a central bore of enlarged diameter which communicates with the inner ends of each of the passages 42a and 42b. Part 4! of the housing has a central cylindrical bore 4la in its lower end which communicates through fitting 43 and conduit 31 with the control pressure of conduit 8. Within the cylindrical bore 4la resides a piston element 44 which has a seal such as an O-ring 45 in a peripheral However, this pressure is relieved spring 41.

grooveforming; a seal between the". pistons andv the wall of the bore., A piston rod 46 extends.

ber OIiJhCilikG, which is in axial alignment with,

the inner end of passage. 42a and is adapted to seat against the end of the passage to close it.

when the rod 46 isshifted to an upperv position. The rod will be: shifted to an upper position when the pressure against the, pressure face of piston 44 is great enough to collapse a resilient member 41 illustrated as a coil spring, which is lodged between lock nut 48 andothe lower end of part 42 of the valve housing. Obviously when the control pressure within conduit 8 exceeds a predetermined value piston 44 will be moved upwardly causing rod 46 to close the passage'42a. Thus, the vent will remain closed and prevent escapeof actuating fluid from the motor of the valve; even; during the intervals at which lever israised from the vent part 32. Upon subsidence of the pressure within conduit 8 the spring 41 will return the piston 44 and rod 46 to. their lower position, thus opening the passage 42a whereby continued rotation of disc 28 will again effect a venting of actuating pressure from the; upper portion of chamber 23.

It is contemplated that the unit, withoutthe time controller [(3, may be installed to control flow through a conduit in. which case the vent for the motor of the valve; will remain open at all times, so that the valve will remain bpen except during those times when the control pressure within conduit 8, exceeds a predetermined value which is dependent upon the strength of This latter type installation may be used for instance in a producing well which flows naturally and wherein the string of flow tubing is equipped with at least two flow connections. In such a well installation, production normallytakes place through one flow. connection,v through a small choke and oftentimes, a

head of salt water, oil or the like builds up, due to the low velocity of flow through the choke containing connection. It is desirable when this occurs to increase the velocity of new in order that the liquid head may be drawn off to again build up the pressure within the flow lines. In this type installation the controller unit of this invention, without the time controller, is installed upon theauxiliary flow pipe with valve 39 connected upstream from the valve member I9 and whenever the pressure within the flow pipe upstream of the valve falls below a predetermined amount the spring 41 forces the rod 46 downwardly to effect venting of the actuating fluid from the upper portion of chamber 23. This results in an opening of 'the motor valve to permit flow through the, auxiliary line increasing the velocity of flow from the well tubing. However;

as flow continues the liquidhead, built up within the well bore; is-d-issipated"and'the control pressure within conduit 8 increases: sure; exceeds a, predetermined amount the actiomofithepressure against piston 44 collapses spring 4! and closes the vent. This effects energization of the. upper portion of chamber 23 and closesthe motor-valve shuttingoff flow through the, auxiliary line.

From the foregoing it will be seen that this invention is one well adapted to attain all of When the pres-- 6 the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure.

It will be understood that certain features and sub-combinations are of utility and'may be employed without reference to other features, and

subcombination. This is contemplated by and iswithin the scope of theclaims.

As many possible embodiments may be madepressure actuated motor-valve connectable in a conduit, the motor-valve including a part exposed to the pressure of the fluid within. the valve and urged thereby in a direction to open the valve, a line connected to the motor of the valve for supplying actuating pressure thereto to hold the motor-valve closed, a vent operably connected to relieve the actuating pressure within the motor of the valve when the vent is opened, a pressure responsive element mounted to control flow through the vent, fittings to supply a control pressure to one face of the pressure responsive element to actuate it when the control pressure exceeds a predetermined value to close the vent, resilient means urging the pressure responsive element toward open position,

a time controller mechanism having a part normally closing the vent and adapted to be moved periodically at predetermined time intervals by said mechanism to open position, whereby the motorvalve is normally closed by the actuating pressure when the vent is closed but is opened by the pressure of the fluid within the valve when the vent is open, and the pressure responsive element when actuated to close the vent prevents opening of the valve in response to the time controller mechanism.

2. A flow controller useable for controlling flow of fluid through a conduit comprising a pressure actuated motor-valve connectable in a conduit, the motor-valve including a part exposed to the pressure of fluid within the valve and urged thereby in a direction to open the valve, a line connected to the motor of the valve for supplying actuating pressure thereto to hold the motor-valve closed, vent means, connected with the motor of the valve, operable to relieve the actuating pressure Within the motor of the valve whereby the motor-valve will be opened by the pressure of the fluid within the valve, means normally closing the vent means and adapted to move to position at desired times, and normally open valve means responsive to pressure downstream from the motorvalve for closing and maintaining closed said vent means when said downstream pressure exceeds a predetermined minimum.

3. A flow controller useable for controlling flow of fluid through a conduit comprising a pressure actuated motorvalve connectable in a conduit, the motor-valve including a part exposed to the pressure of fluid within the valve and urged thereby in a direction to open the valve, a line connected to and adapted to supply actuating pressure to the motor of the motorvalve, vent means, connected with the motor of the motor-valve, operable to relieve the actuating pressure within the motor whereby the motorvalve will be opened by the pressure of the fluid within the valve, a valve means interposed in the vent means connection including a pressure responsive element mounted to control flow through the vent, fittings to supply a control pressure to'one face of the pressure responsive element to move it into position to close the vent means, a resilient element urging the pressure responsive element against said pressure, additional serially arranged means normally closing the vent means but adapted to open the vent means at predetermined time intervals, whereby the motor-valve is normally held closed by the actuating pressure when the vent is closed but is opened by the pressure of the fluid within the valve when the vent is open, and the pressure responsive element when actuated to close the vent prevents opening of the valve in response to the time controller mechanism.

4. A flow controller useable for controlling flow or" fluid through a conduit comprising a pressure operated motor valve adapted to be interposed in a conduit, said motor-valve including a motor unit made up of a chamber with a diaphragm dividing the chamber into two parts, a valve stem with a part having a power transmitting connection with one side or the diaphragm, a valve member carried by the stem adapted to control the flow of fluid through a conduit in such manner that the force due to the pressure differential thereacross when closed is transmitted through the stem at least in part to the diaphragm in a direction to unseat the valve m;mber, a line connected to the chamber for supplying actuating fluid on the side of the diaphragm to move it in a direction to close the valve, a vent operably connected to relieve the pressure within the said pressurized part of the chamber when the vent is open, a piston element mounted to control flow through the vent and having one face exposed to a control pressure and adapted to be ctuated thereby when the pressure exceeds a predetermined value to close the vent, resilient means urging the piston toward open position, and a time controller mechanism having a part adapted to normally close the vent downstream from the piston and to be moved periodically at predetermined time intervals by said mechanism to open position, whereby the motor-valve member is normally held closed by the actuating pressure acting on the diaphragm when the vent is clcsed but is opened by said pressure d ierential when the vent is open, and the piston element when in vent closing position prevents opening of the valve in response to the time controller mech- 'anism.

An apparatus for controlling flow of fluid through a conduit comprising a pressure operated motor-valve adapted to be interposed in a conduit and a time controller mechanism, the motorvalve inclu f g: a valve body with a valve member therein operable to control flow of fluid through the body, a part associated with the valve member and exposed to the pressure of the fluid within the valve and adapted to be moved thereby in a direztion to unseat the valve memher, a pressure responsive member operably connected to the valve member in the motor-valve, means to energize the pressure responsive member to urge the valve member toward seated position; a vent for ale-energizing the pressure responsive member, the time controller mechanism having a part adapted to normally close the vent and to be moved periodically at predetermined time intervals by said mechanism to open position, a pressure responsive element mounted to control flow through the vent upstream of the time controlled part, said pressure responsive element having one face exposed to a control pressure and urged thereby in vent closing di rection, resilient means urging the pressure responsive element toward open position, whereby the motor-valve is normally held closed by the actuating pressure when the vent is closed but is opened by the pressure of the fluid in the valve when the vent is open, and the pressure responsive element when actuated to close the vent prevents opening of the valve in response to the time controller mechanism.

6. A flow controller useable for controlling flow of fluid through a conduit comprising a motorvalve connectable in a conduit, the motor of said motor-valve having means for urging the valve member of the motor-valve toward open position, a line connected to the motor of the motor-valve for supplying actuating pressure thereto to actuate a pressure responsive means for closing the motor-valve, vent means, connected with the motor of the valve, operable to relieve the actuating pressure within the motor of the motorvalve whereby the motor-valve will be opened by the first mentioned means, means including a normally open pressure responsive valve responsive to the pressure downstream from the motor-valve and a time controlled valve normal 1y closing the vent means, adapted to open the vent means at predetermined time intervals when the pressure downstream of the motor valve is less than a predetermined maximum.

7. A flow controller useable for controlling flow of fluid through a conduit comprising a pressure actuated motor-valve connectable in a conduit, the momr-valve including a part exposed to the pressure of fluid within the valve and urged thereby in a direction to open the valve, a line connected to the motor of the valve for supplying actuating pressure thereto to hold the motor-valve closed, vent means, connected with the motor of the valve, operable to relieve the actuating pressure within the motor of the motor-valve whereby the motor-valve will be opened by the pressure of the fluid within the valve, means including normally inoperative vent closing means responsive to downstream pressure to close the vent means when the downstream pressure is less than a predetermined maximum, and time controlled means normally closing the vent means, adapted to move to open position at predetermined time intervals.

HENRY U. GARRETT. CLIFFORD M. PETERS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

